<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>animation</title>
     <style>
        * {
            padding: 0;
            margin: 0;
            border-style: none;
        }
        .box {
            width: 330px;
            height: 300px;
            border: 1px solid;
            margin: 100px auto;
            display: flex;
            align-items: center;
            justify-content: center;
         }

         .line {
            width: 10px;
            background-color: peru;
            animation: widtMete 1s infinite linear alternate;
         }
         .line:nth-of-type(2) {
            margin: 0 10px;
            animation-delay: .4s;
         }
         .line:last-child {
            animation-delay: .6s;

         }
         @keyframes widtMete {
             from {
                height: 0;
             }
             to {
                height:20px;
             }
         }
     </style>
</head>
<body>

    <div class="box">
        <div class="line"></div>
        <div class="line"></div>
        <div class="line"></div>
    </div>
    
</body>
</html>